Pneumatic tire.



A. DOW. PNBUMATIC TIRE.

APPLICATION FILED AUG.1s, 1913.

Patented Dec. 15,1914.

Y2 SHEETS-SHEET 2.

UNITED STATES PATENT oEEicE.

ALEXANDER DOW, OF NEW YORK, 'N. Y., ASSIG-NOR T0 HELIX TUBE CO., INC., A

' CORPORATION OF NEW YORK.

PNEUMATIC TIRE.

Specication of Letters Patent.

Patented Dec. 15, 1914.

Application filed August 18, 1913. Serial No. 785,421.

. State of New York, have invented certain new Improvements in PneumaticTires, of which the following is a specification.

My invention relates to an improvement in pneumatic tires and hasparticular reference to a means for preventing the escape of air fromthe interior of the tire after the outer shoe, or casing, bursts fromthe internal pressure.

Broadly speaking, the subject matter of my invention pertains to a meansof giving to the tire a reserve capacity, by embodying in it elementscapable of resisting the pressure of the confined air and preventing itsescape, which elements are under no tension or bursting stress in anydirection and only perform their function when the normal means adaptedto retain the air pressure have' failed.

disposed in a manner, either within the casing, or in the inner tube, orin a tire protector located between the inner tube and.

Vthe casing, not to be under any tension as the result of the compressedair within the tire.

The purpose of my invention is to have all thebursting stress of thecontained air Aexerted upon the fabric of the shoe, and no tension ofbursting stress in any direction exerted upon the reserve fabriccontained in the tire, so that in case the working fabric of ,the shoefails or ex lodes as the result of wear or weakening o the fabric, thatportion of the inner tube, or tire protector, adjacent to the rupturedportion of the shoe can expand in any direction to a certain degree,after which it can expand no further and its strengthi will serve toprevent the explosion of the inner tube and the release of the airwithin it.

In my previous application I have described the method of embodying thefabric in corrugations or otherwise so that under the pressure of theair this fabric will be under no tension whatever until after the' shoecontaining the working fabric has failed. My present invention, however,differs from this, in that instead of having the reserve fabric in aneutral condition, or without tension, while the fabric of the shoe isin tension, the fabric of the inner tube or tire protector. is placedunder al condition of compression.

In my previous application referred to, one method of employing areserve fabric Yin the tire was specifically shown and described asbeing embedded within the rubber ofthe inner tube in the form of helicalcorrugations, the exterior of the tube being of circular form and theinterior either circular or corrugated. As constructed in this way, thefabric was maintained in -a corrugated form when the tire was iniiated,and was not under any tension, but was entirely slack at all points. Thepurpose of the corrugations being helical as described is to give to thetube such a circumferential elasticity as may be needed to permit of thebending of the tube from a straight to a circular form without renderingthe reserve fabric tense, and also to permit it to remaincircumferentially slack after its inflation in tire of varyingdiameters. In the inner tube which is the subject of this invention,however, the vhelically 'corrugated fabric is covered with rubber withinand without, so that bothA the interior and exterior of the tube iscorrugated, the walls of the tube being practically of uniformthickness. Upon inlating this tube within the shoe the corrugated fabricis flattened out by the air pressure, and the tube lies snugly againstthe interior of the shoe, with the reserve fabric of Vthe tubeyin astate of compression, while the fabric of the shoe is in a state oftension. In consequence of this, upon the bursting of the outer shoe orcasing, the inner tube is capable of expanding in any direction, at thepoint where they casing has parted, until the fabric has lost thecompression it was under, and has assumed the necessary tension toretain the air pressure of the tire. Another advantage of placing thereserve fabric in a state of compression is that it is thereby renderedmore dense and becomes a greater protection against the puncture of therubber of the inner tube. Further, this reserve fabric upon encounteringa puncturing instrument is not apt to suffer damage, as its slack contcalculated by a determination of the dition permits of its motion to aconsiderable degree before becoming sufficiently tense to have a holemade in it.

I have illustrated my invention in the accompanying drawings,designating the parts by numerals, referring to like parts by likenumerals.

In these drawings Figure l is a side elevation of an inner tube, partlyin section and la, containing an embodiment of my invention;

Fig. 2 is a section of the wall of the inner tube on the line a-Z),showing the corrugated reserve fabric with rubber on the exterior andinterior of it; Fig. 3 is a cross g5 section of the inner tube ascontained within a casing, and before the inner tube is inflated. Fig. 4is the same View with the inner tube fully inated.

In Fig. l the inner tube is shown as bega ing formed in helicalcorrugations extending about it. A section of this is shown exhibiting acircumferential wave.

In Fig. 2 1s shown a section of the corrugations on the line a-'b, whichisithe true form of the corrugations, and shows the center line of thefabric as being in a uniform wave.

In Fig. 3, 1 is a section of an ordinary shoe or outer casing of apneumatic tire,

attached to the'rim Q, mounted on the felly 3. 4 is a section of theinnerl tube, in the corrugated form provided with reserve fabric. 5 isthe interior rubber wall of the tube 4'. C is the layer of the reservefabric. 'i'

is the outer or protecting layer of rubber on the exterior of the tube.In this figure the inner tube 4 is shown without being inflated.

In Fig. 4, 1 is the casing, attached to the 4o rim 2, mounted on thefelly 3, and containing the inner tube 4 after the same has beeninflated. In this view, the corrugations having been flattened out, thewalls of rubber 5 and 7, and the reserve fabric 6, lie

in concentric layers, in a state of compression, snugly fitting theinterior of the casing 1. The fabric in this case, as in my copendingapplication above referred to, has a diagonal of the weaveextendingparallel with the crests of the corrugations or, in

other words, the fabric is laid on the bias, thereby to yield in anydesired direction and take up the strainl of inflation. This will permitthe fabric to expand circumferentially, laterally or otherwise upon thenorembodiment of the reserve compressed fabric in the shoe or innertube, it can also be located in an interior tire protector, between thetube and the outer casing, thus limiting the further expansion of theinner tube beyond ay certain prescribed amount when the normal pressureresisting fabric has failed.

I realize that considerable variation is possible in the method oflaying the fabric within the tire without departing from the spirit ofmyvinvention, and I do not, therefore, intend to limit myself to thespecific arrangement here shown and described for incorporating thecompressed reserve fabric in the tire. It is immaterial whether thesehelical corrugations be regular or irregular. the purpose of theirparticular arrangement being to afford a universal compressed conditionof the reserve fabric adjacent to any point where the working fabricmaypart, which reserve fabric can then most readily lose its compressionand become under tension, and prevent further expansion of the tube. Itis further apparent that instead of corrugations, hemisphericaldepressions could be made in the fabric or other forms which would giveto it a possibility of universal extension, without departing from thespirit of my invention.

While I have described specifically the use of a helicalcorrugatedreserve fabric in the inner tube or tire protector, such anembodiment can be made in the outer casing as to effect a similarresult, by having contained in the outer casing certain layers of fabricunder tension, and another series of layers under compression when thetire is inflated. Under these circumstances, the tense working layers offabric can fail and part upon which the reserve layers can take thestress and prevent the rupture of the air containing tube.

I-Iaving set forth the nature and objects of my invention what I claimand desire to secure by Letters Patent is:

l. An inner tube for pneumatic tires formed of rubber, the rubber beingcorrugated diagonally, a layer of fabric embedded in th'e body andextending throughout the entire body portion thereof, said fabric beingcorrugated to conform to the c0rrugations of the rubber in which it isembedded and having the diagonal of the weave extending along the crestsof the corrugations.

2. An inner 'tube for a pneumatic tire formed ofy rubber, the rubberbeing corrugated diagonally, a plurality of layers of fabric embedded inthe body and extendin throughout the entire body portion thereo saidfabric being corrugated to conform to the corrugations of the rubber inwhich it is embedded and having the diagonal of the Weave extendingalong the crests of the corrugations.

3. An inner tube for a pneumatic tire onally corrugated whereby the tubeis unformed of rubber and diagonally corruder compression in alldirections when ingated throughout its entire length, a layer flated ina shoe of proper size and may exof fabric embedded in the body portion,pand circumferentially and longitudinally.

5 the said fabric being on the bias with re- In testimony whereof Iaifix my signature 15 spect to the corrugations. in presence of twowitnesses.

4. An inner tube for a pneumatic tire ALEXANDER DOW- l yformed ofresilient material and having VV'tnesses:

embedded .therein layers of fabric, both the SAMUEL KAHN,

10 resilient material and the fabric being diag- GEORGE L. Monius.

